How TI DLP Pico technology fits within wearable display systems

Hello. This is Juan Alvarez, and this is part 3 of the webinar Wearable Displays with TI DLP Pico Technology. In this section, we will be looking at the block diagram of the DLP Pico technology. Then we will be looking at DLP technology overall. And finally, we'll be wrapping it up with the benefits of DLP Pico technology as it relates to wearable displays.
If you haven't already and if you feel you want to, you can also check out the other two parts of this webinar series. The first one was Wearable Display Systems, where we cover augmented reality, virtual reality, optical architecture, and the system considerations. And then on part 2, we covered wearable display applications. That includes applications, markets, and segments of wearable displace.
To start looking at how DLP technology is incorporated in a wearable display system, we start off with the block diagram. What you'll see here is the DLP Pico technology is in the heart of the display system. And it all starts with the DLP digital micromirror device.
The DMD will be driven by the display controller, which is responsible to supply all the digital signals to drive the DMD itself. In addition, we have a power management device that is responsible for driving all the voltages to the DMD, to the illumination driver, and also to the display controller as well. Now, the video signal that comes to the display controller comes from either a front-end multimedia processor, but it's probably more common to see an application processor driving the signal for a wearable display application.
The system itself will be broken down in two parts-- electronics, and an optical system. The optical system includes the DMD, as noted before; in some cases, the flash memory; and for sure, it will include the LED illumination. For this type of application, LED is commonly used. And it will vary depending if it's a VR or an AR type of application.
This setup will support either a monocular or biocular system. And again, monocular is for one eye. And biocular is for two eyes, but the content is exactly the same on the two eyes. For a biocular type of system, you will have two DMDs. You would have two separate DLP display controllers, and an application processor feeding both signals independently.
Now, let's take a step back and let's look at DLP technology as a whole. As mentioned earlier, it all starts with a DLP chip or DMD. And the DMD is responsible to create the image that you see displayed either in a wearable display, or in cinema, or whatever have you. It is comprised of millions of micromirrors, microscopic mirrors. And they switch back and forth in an on or off position to either steer light towards the focal point or away by generating a 1 or 0 type of output.
DLP technology actually can cover a wide range of wavelengths-- from UV, ultraviolet, up to NIR, Near Infrared Light, so wide gamut of wavelengths that it supports. And it also is also light agnostic. So it can support either lamp, or laser, or LED type of systems.
So now, let's take a look at DLP products at a high level, and what it enables in all different types of categories. These are four major categories. The first one is DLP enterprise and cinema displays. These categories includes projectors that are found in offices, classrooms, large venues, and digital cinemas.
In fact, Dr. Larry Hornbeck received his Oscar on February 7, 2015 at the Academy Annual Scientific and Technical Awards for inventing the digital micromirror device, the basis of the DLP Cinema chip used in the majority of theaters, including IMAX. These are great proof point of the quality that DLP technology is able to enable across the board.
Second category is DLP automotive. And DLP automotive are DLP chips enabled in the car that can either provide a head-up display, can provide free-form center consoles, and can also enable headlights displays as well.
The other category is DLP advanced light control, which are non-display applications specifically for industrial segment, which include 3D machine vision, 3D printing, space spectroscopy, and photolithography. One of the benefits here and across the board is the fast switching speed, which is the one that allows to enable all these new type of applications in this arena.
Now, last but not least, you have the DLP Pico products, which are the ones that are used for head-mount displays for wearable displays. And DLP Pico products enables the smallest, lowest power DLP display solution and great image quality spawn from DLP Cinema technology. Specifically, the wearable displays are enabled by DLP Pico products. Now, we're going to look at a few applications that are enabled by this technology.
So here they are, a few applications that are enabled by the DLP Pico technology. These applications include mobile, smart TV, Pico projectors, tablet and smartphones, commercial gaming, smart home, digital signage, and aftermarket head-up display. If you are curious to learn more about these applications, we encourage you that you go to ti.com/picoapplications, where we have information on most of these applications on our website.
Now that we spent a few minutes looking at DLP technology overall and looking at some of the applications or some of the other applications that DLP Pico technology enables, let's go back and talk about how DLP Pico technology benefits the wearable display marketplace. This slide here is specifically focused for VR applications. And here are the highlights of this slide.
Number one, we actually have products shipping in the market today. So there are VR products shipping in the market today from utilizing DLP Pico technology. A good example of that is the Avegant Glyph. Secondly, the DLP Pico products offer smaller form factor than the traditional VR solution, which you are using a smartphone screen. So if there's a need for smaller size above and beyond anything else, then DLP Pico products provides a good solution for that.
In fact, the DLP Pico solution can also support up to or approximately 80 degree field of view with a 0.47-inch 1080p DMD panel. And we're going to be looking at some of those details on the next slide, which I'm assuming that you're going to be very curious about. Also, the DMD itself has a low panel latency, and the display control in the DMD can enable 1 frame latency for TRP products, which is quite fast-- about 8.2 milliseconds worth of time frame by frame.
This helps quite a bit, specifically for the following three categories. The first one is the first-person viewer. And we looked at that category earlier in part 1 or 2. And so we looked at that earlier. And first-person viewer, for those of you who don't know, it's mainly a category that is focused on manning a drone. And so latency is really key, making sure that whatever you see on your display, on your eyes, is exactly the same and very quickly the same as what the drone is seeing on a camera.
So that's first-person viewer. Drone control is going to be a more specific use case for just first-person viewer. And then gaming is going to be-- also, latency is important, where you're trying to get the quickest refresh rate you can do, the smallest latency you can, so that you can experience the best gaming experience and be able to respond to whatever you see on the screen itself, or on the display, in this case.
In terms of market highlights for VR, what we're experiencing in general is gaming and immersive experience are two really key important factors for this type of category. We're seeing interesting FPV, First Person Viewer. We're looking at a lot of excitement on the personal theater experience. Small form factors are important. People want to make sure that it's comfortable, that it doesn't take a lot of space.
Low latency is really important, as well as a good head tracking. Head tracking with low latency kind of goes hand by hand because when you move your head, you want to be able to have your display respond as fast as you can on that as well. So in summary, these are a few benefits that DLP Pico technology offers for VR applications as well as some market highlights for this one.
So previously, we mentioned that 80 degree field of us possible with the 0.47-inch 1080p DLP7410 DMD. And these charts here demonstrate how we get there. And so what we have here are two graphs-- one for the 0.3 720p. That's on the left side. And then we have the chart for the 0.47-inch 1080p DLP4710 on the right side.
On the x-axis, we have pupil diameter. So that's how big the diameter is going to be at the entrance of the waveguide, for example. Or if it's a direct view, this will be the pupil diameter itself. And then on the y-axis, we have diagonal field of view in degrees. So that is what we have. So we have the field of view, and then we have the pupil diameter.
And then we have the F number. And these are the graphs that have different colors. And the F number is the ratio of the lens focal length to the diameter of the entrance of the pupil. So depending on the F number, you're going to get different field of view positions.
So let's go, for example, where we assume a 5 millimeter pupil diameter. You see that we can pretty close to 80 degree field of view. But then if we wanted to target a larger pupil diameter, maybe around 7, then that field of view is going to go down-- maybe to the 50 degree field of view. So it really depends on the design here, and really depends what you want to do.
And of course, if you look at panel size, panel size will directly impact field of view for sure. So on the 0.3-inch 720p for 5 millimeter, what you will see is that that can attain 50 degree field of view compared to almost 80 degree field of view. And then for around 7 pupil diameter, you get about a little bit over 30 degree field of view. So there you have it-- depends on what you want to achieve, but 80 degree field of view is possible depending on the variables that you are trying to manage there.
So just one word of caution-- depending on the pupil diameter, you will have to have different mechanical elements to be able to get the pupil diameter aligned with the pupil diameter of the eye itself. So for example, a 5 millimeter pupil will require much more mechanical elements than a pupil diameter of 7 millimeter.
Now, let's switch gears, and let's talk about DLP Pico products for augmented reality applications. The first thing that we want to highlight is waveguide is definitely the common approach here for the industry. Combiner can be used, but the waveguide is the common approach.
The benefit of using a waveguide is that it expends the eye pupil by three to five times. This means that if you have a pupil diameter designed for, let's say, 5 millimeters, as we showed in the previous graph, then the effective pupil diameter, let's say, [INAUDIBLE] by three would be 15 millimeters. And what this means is that you can use the benefits of 5 millimeter pupil, which will get you a pretty big field of view. And then from an eye box point of view, you will be able to get a larger eye box, a larger pupil, on the eye itself.
And so pupil expansion can mitigate the need for user adjustments of inter-pupillary distances. It also enables flexible system packaging design. And so that is a benefit as well. And we have seen implementations on DLP Pico products today using waveguide. An example of that is Vuzix. And so you can look at their information. But they are using DLP Pico technology today.
One thing here for waveguide is-- and this is just a note-- is that there's a lot of multiple proprietary implementations, and needless to say that it is quite difficult to design a waveguide from the beginning. And also it may be difficult to navigate the multiple proprietary implementations available today. And so when you look at this, be sure to look at different options available out there and who are the folks that provide those options. As noted earlier, for example, Vuzix has one of these proprietary waveguide implementations available.
And then the other thing to note between VR and AR is that AR will require a higher lumens then VR would. So VR, we're only talking about maybe less than a lumen, while for example, for an AR application, there's a lot of inefficiencies as you go through the waveguide. And we really are talking about a 10 lumens type of implementation to kind of get just a fraction of that into the pupil's eyes.
Another important point about augmented reality is high contrast. High contrast is important because it really enables a seamless experience between the display and visual surroundings. A low contrast ratio would look like some sort of a box. And the transparency of the display itself would be lost, versus a high contrast ratio will enable a seamless experience. The good news is with DLP Pico technology, it has extremely high contrast ratio, which means that for this type of application, it's a very good fit.
So in summary, for augmented reality, we're looking at two things-- waveguide as a common approach, and then high contrast as a key requirement and also benefit for DLP Pico technology. Now, in terms of market highlights, what we've seen is different segments in this industry-- industrial, medical, military applications-- these augmented reality can be either information-centric, or more of an object detection type of applications.
Seamless displays is a key requirement. Low latency is also important, similar to VR. We look at head tracking. So as you turn on your head, you have to have low latency. And obviously, greater than, let's say, 40 degree field of view is what we're seeing in terms of the need for the industry.
And for example, you had Google, which was more of a 14 degree field of view. But the more field of view you get, the more useful it is. And it goes from a secondary display up to a primary display that can be used for more of a productive usage.
OK, now that we covered AR and VR as it relates to DLP Pico technology, let's look at a summary of the benefits. The first one is high optical efficiency. DLP Pico technology has very good LED brightness efficiency. And that brightness efficiency is increased as brightness goes up. Specifically for augmented reality systems where we're talking about 10 lumens, we see a good benefit there in terms of illumination-- so good overall low system power on a given brightness.
The next benefit is fast pixel switching speed. We talked earlier how important it is to have a low latency in AR and VR systems. And DLP Pico technology can support 1 frame buffer for TRP products, which means 120 hertz or 8.2 milliseconds. This definitely helps correlate the head tracking with the display-- so if you're doing anything, if you're moving around, being able to make sure that the display itself is as fast as the movement of the head.
The second one is fast moving display for gaming. And in fact, the technology itself is capable to display up to 240 hertz if need be. And some applications may require even a faster refresh rate. And finally, last but not least, it's also about high color refresh rate. So all these color sequencing is sequential. And DLP Pico technology is able to provide all these colors quickly where there should be no issues at all, whatsoever.
The next benefit is high contrast. And we just discussed that one earlier. And the point here is that specifically for augmented reality, you do want to make sure that the display is seamless and seamlessly integrated between the display and the real world. And there's an example here that has been highlighted, where the left image shows low contrast ratio, and the right image shows a high contrast ratio.
In addition, we have the IntelliBright image processing algorithms that are for TRP devices. And these devices enable either brighter or lower power displays, helping out with better efficiency or lower power for these demanding applications.
And finally, we're talking about fill factor. And fill factor, what it allows, it allows a very small gap between each pixel. And when the display so close to your eye, we definitely do not want to have any sort of a pixellation happening to you.
Now that you have looked at the DLP Pico technology benefits for wearable displays, let's go into products. So this table here gives us the product line offering that you can use today. The best and easiest way to use this is by, for example, selecting resolution. It means whatever resolution you feel that is best for your application. And then we also have the maximum field of view given some assumptions that are highlighted in this slide.
In general, this entire slide is under application node called DLP Technology for Near-eye Displays. What we noted is that probably the chipset that is most popular for this one is the 0.3-inch 720p. Having said that, it really depends on the application. And we've seen needs for up to 1080p, and then down to 0.2 wide VGA as well.
Now, you can learn more online at our Applications web page, where you will find useful information about features and benefits about how to get started now; key technical resources; and in general, all kinds of information about wearable displays. You can go to ti.com/picoapplications. In fact, there's a link there to the DLP Technology for Near-eyed Displays whitepaper.
So this is the end of the webinar for DLP Pico technology in the wearable display market. Here's a quick summary of what we've seen in all three parts of the webinar itself. The first one is that there's a great market right now for VR and AR opportunities. And these are enabling new, exciting applications.
Secondly, there are definitely quite a bit of design considerations to take care of, including optical architecture and other key factors, which include image quality, display latency, and active power from a system level. And then also, there's also considerations to think about from an eye point of view, including the field of view, inter-pupillary distance, and pupil size.
For sure, DLP Pico products offer display components that meet needs for both VR and AR-- specifically, high contrast ratio, low latency, and high optical efficiency, and low power. Now, the best way to get started today is buying one of the DLP Pico evaluation kits today. And to do that, just go to ti.com/DLP. And then go to Tools, and then you'll find quite a bit of offering there.
In addition to this webinar, you can learn more about DLP technology by visiting us at ti.com/DLP. You can also type DLP2010, DLP3010, or DLP4710 to look at the different products for the product line. You can also start a new project or learn more about the technology by typing ti.com/gettingstarted. You can also learn about all the different applications supported by DLP Pico technology at ti.com/picoapplications. And just in general, you can learn more about TI products at ti.com. Thank you, and have a great day.

Description

August 25, 2016

There are quite a bit of system considerations to design a wearable display. We designed this training based on the questions that product development managers and engineers are asking themselves about this attractive application.